Quite a few papers in the two journals, The Journal of Agricultural Education and Extension and The Journal of Sustainable Agriculture, deal with ideas for future education towards sustainability and extension and advisory service as facilitation. Both subjects include participatory learning and/or farming systems approaches based on systems theory. We argue that these approaches overlook the content of the agro-scientific expert knowledge itself as a necessary object for reflection. Inspiration is gained from the sociology of science and technology to "open the black box" of the agro-scientific expert knowledge. It is a question of achieving a symmetric view of the knowledge of experts and non-experts. Seen from a constructivistic point of view there is no principal difference between the valued, situated and contextual character of the two types of knowledge. Professionals/experts should therefore, also be able to reflect on their own body of knowledge. We describe and discuss our experiences of including awareness about the experts' knowledge whilst teaching an agro-scientific course on organic farming at the Royal Veterinary and Agricultural University in Denmark. (Contains 1 note.)